Highway high and steep slope roadbed structure

Abstract

The utility model discloses a highway high and steep slope roadbed structure, belongs to the field of slope protection, and aims to shorten the construction period and reduce the construction difficulty. Comprising a concrete expanded foundation poured in a slope toe foundation pit of a side slope, stand column steel bars are bound on connecting steel bars in the concrete expanded foundation, the stand column steel bars and concrete are poured into a whole to form a concrete plate, a pouring cavity is defined between the concrete plate and the side slope, and sand gravels are filled at the bottom of the pouring cavity to form a permeable cushion layer. Light foam concrete is poured in the space, located on the permeable cushion layer, of the pouring cavity to form a filling body. The filling body formed by filling the light foam concrete is light in self weight, the stability of the high and steep slope roadbed is improved, and the filling body can well adapt to the conditions that the soil texture condition of the high and steep slope is poor and the soil body is unstable. The light foam concrete filling excavation volume and the filling volume are greatly reduced, the construction period is shortened, and the construction safety and economical efficiency are both improved. The water-permeable cushion layer is good in drainage effect, and the stability of the high and steep slope roadbed can be better guaranteed.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of slope protection, specifically is highway high and steep slope subgrade structure. BACKGROUND

[0002] In mountainous area, the terrain is steep, the slope is washed by water flow for a long time, the soil condition is poor, the foundation bearing capacity is too low, and the overall instability and collapse of the embankment and foundation are easily caused. At present, two forms are usually used to protect the high and steep slope of the highway, one of which is the conventional embankment type retaining wall protection, as shown in the drawings, the anti-skid pile 14 or the gravity type retaining wall 13 is constructed at the slope toe to permanently protect the slope, the soil is filled between the retaining wall 13 and the slope, and the upper structure layer of the subgrade is constructed on the backfill. However, the structure, the concrete uses large volume, due to the limited construction site in the steep slope section, the large volume of concrete is difficult to construct in the limited construction site area, and the stability is difficult to guarantee, the engineering scale is large, the construction period is long, and the economy is poor; the other form is high filling and high excavation, as shown in the drawings, the hierarchical excavation support 15 is carried out on the upper structure layer of the subgrade, which is not conducive to the operation safety and environmental agency of the existing highway, increases the construction difficulty, and the cost is high. Figure 1 Figure 2 The utility model discloses a kind of highway high and steep slope subgrade structure, shorten construction period, reduce construction difficulty. UTILITY MODEL CONTENT

[0003] The utility model discloses a kind of highway high and steep slope subgrade structure, shorten construction period, reduce construction difficulty.

[0004] The utility model discloses the technical scheme in the embodiment is as follows: highway high and steep slope subgrade structure, including the foundation pit that is excavated in the slope toe outside, the concrete enlarged foundation that is poured in the foundation pit, the vertical extension column steel bars that are tied on the connecting steel bars embedded in the concrete enlarged foundation, the column steel bars are integrally formed with concrete pouring and form concrete slab, the pouring cavity is enclosed between the concrete slab and the slope, the cavity bottom of pouring cavity is filled with gravel and forms water-permeable cushion, light foam concrete is poured in the space on water-permeable cushion and forms filling body;Water interception ditch is excavated in the slope toe outside, and water interception ditch is located in the outside of concrete slab;Drainage hole is reserved on the concrete slab, and the inner end of drainage hole extends to water-permeable cushion, and the right end extends to the outside of concrete slab.

[0005] Further, the cross section of the concrete enlarged foundation is inverted T shape.

[0006] Further, the slope includes slope surface, step surface at the top of slope surface and slope toe surface at the bottom of slope surface;Anti-skid fixed nail is punched at the slope surface, and the left end of anti-skid fixed nail is poured into filling body, and the right end is inclined downward and punched into mountain.

[0007] ​Furthermore, a layer of metal mesh or impermeable geomembrane is laid on the permeable cushion layer to form a reinforcing layer.

[0008] Furthermore, an impermeable geomembrane is laid within the filling material to form a second reinforcing layer.

[0009] Furthermore, a glass fiber mesh is laid in the infill to form a third reinforcing layer; along the vertical direction, the third reinforcing layer aligns with the stepped surface of the central slope.

[0010] The beneficial effects of this utility model are as follows: The lightweight foamed concrete filling material has a low self-weight, which reduces the load-bearing capacity requirements of the concrete spread foundation, thereby improving the stability of steep slope subgrades. Its light weight also makes it better suited to conditions with poor soil quality and soil instability on steep slopes. The excavation and filling volume of lightweight foamed concrete filling is greatly reduced, the construction period is shortened, and both construction safety and economy are improved. By filling the filling material with gravel and draining the water collected in the permeable cushion layer through drainage channels set in the concrete slab, the permeable cushion layer, laid at the bottom of the cavity, is located at a low position and has a wide area, which facilitates permeability and water collection, resulting in good drainage and further ensuring the stability of steep slope subgrades. Attached Figure Description

[0011] Figure 1 A schematic diagram illustrating the protection measures for existing embankment retaining walls;

[0012] Figure 2 This is a schematic diagram of the existing high embankment and high protection system;

[0013] Figure 3 This is a schematic diagram of the present invention.

[0014] In the diagram, the slope is 1, the slope surface is 1A, the step surface is 1B, the slope toe is 1C, the concrete spread foundation is 2, the concrete slab is 3, the drainage channel is 4, the permeable cushion layer is 5, the infill is 6, the intercepting ditch is 7, the first reinforcement layer is 9, the second reinforcement layer is 10, the anti-slide fixing nail is 11, the third reinforcement layer is 12, the retaining wall is 13, the anti-slide pile is 14, and the graded excavation support is 15. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0016] In this utility model, the terms "left," "right," "vertical," "up," "down," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the appendix. Figure 3 The orientation or positional relationship shown is for the purpose of describing the present invention only, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0017] Highway subgrade structure with steep slopes, such as Figure 3 As shown, the structure includes a foundation pit excavated on the outer side of the slope toe of slope 1, a concrete enlarged foundation 2 poured into the foundation pit, vertically extending column steel bars tied to the pre-embedded connecting steel bars in the concrete enlarged foundation 2, the column steel bars and the concrete being poured together to form a concrete slab 3, the concrete slab 3 and the slope 1 forming a pouring cavity, the bottom of the pouring cavity being filled with gravel to form a permeable cushion layer 5, and lightweight foamed concrete being poured into the space of the pouring cavity on the permeable cushion layer 5 to form a filling body 6; a water interception ditch 7 is excavated on the outer side of the slope toe of slope 1, the water interception ditch 7 is located on the outer side of the concrete slab 3; a drainage channel 4 is reserved on the concrete slab 3, the inner end of the drainage channel 4 extends to the permeable cushion layer 5, and the right end extends downward at an angle to the outer side of the concrete slab 3.

[0018] The column reinforcement bars inside the concrete slab 3 are tied to the connecting reinforcement bars pre-embedded in the concrete enlarged foundation 2, so that the concrete slab 3 and the concrete enlarged foundation 2 are connected as one, which not only forms a pouring cavity, making the concrete slab 3 a template for pouring lightweight foamed concrete, but also makes the concrete slab 3 protect the infill 6 and the permeable cushion layer 5 on the outside.

[0019] The lightweight foamed concrete filling body 6 has a light weight, which reduces the bearing capacity requirement of the concrete enlarged foundation 2, thereby improving the stability of the roadbed on steep slopes. Its light weight is also better suited to the poor soil conditions and soil instability on steep slopes.

[0020] Compared to traditional anti-slide piles or gravity retaining walls for permanent slope protection, lightweight foamed concrete significantly reduces excavation and filling volumes, shortens the construction period, and improves both construction safety and economy. Furthermore, compared to traditional high-fill, high-excavation methods, the superstructure layer of the roadbed is directly above the fill material 6. By excavating the slope first and then constructing the superstructure layer, the impact on the existing highway operation is minimized, and the elimination of staged excavation reduces construction difficulty and costs.

[0021] Traditionally, drainage is achieved by pre-draining holes in the filler 6. In this invention, gravel is filled beneath the filler 6, and water collected in the permeable cushion layer 5 is drained through drainage channels 4 on the concrete slab 3. Because the permeable cushion layer 5 is laid at the bottom of the cavity, at a low position and with a wide area, it facilitates permeability and water collection, resulting in better drainage and ensuring the stability of the steep slope subgrade. The intercepting ditch 7 is used to collect the water discharged from the slope and guide it to the corresponding river or other drainage system.

[0022] To improve the stability of the concrete spread foundation 2, preferably, the cross-section of the concrete spread foundation 2 is inverted T-shaped.

[0023] To improve the stability of the filler 6 and prevent it from sliding along the slope 1, preferably, the slope 1 includes a slope surface 1A, a step surface 1B at the top of the slope surface 1A, and a slope toe surface 1C at the bottom of the slope surface 1A; anti-slip fixing nails 11 are driven into the slope surface 1A, with the left end of the anti-slip fixing nail 11 cast into the filler 6 and the right end driven into the mountain body at an angle downward.

[0024] A layer of metal mesh or impermeable geomembrane is laid on the permeable cushion layer 5 to form a reinforcing layer 9. Since the permeable cushion layer 5 is formed by filling with lightweight foamed concrete, laying metal mesh or impermeable geomembrane on the permeable cushion layer 5 can improve the flatness of the top surface of the permeable cushion layer 5 and minimize the seepage of lightweight foamed concrete into the permeable cushion layer 5, thus affecting its permeability. At the same time, the metal mesh or impermeable geomembrane is combined with the lightweight foamed concrete to improve the crack resistance of the filling body 6.

[0025] To further enhance the crack resistance of the filler 6 and reduce reflective cracks, an impermeable geomembrane was laid inside the filler 6 to form a reinforcement layer 2 10.

[0026] To further enhance the crack resistance of the filler 6, a glass fiber mesh is laid inside the filler 6 to form a reinforcing layer 3 12; along the vertical direction, the reinforcing layer 3 12 is aligned with the step surface 1B of the central slope 1.

[0027] The specific construction process is as follows:

[0028] 1. First, thoroughly remove the surface layer of weeds, trees, humus, etc. from the slope. After removing the colluvial layer, excavate steps with a width of not less than 5m to form the slope surface 1A, the step surface 1B, and the slope toe surface 1C of slope 1.

[0029] 2. Excavate drainage ditches and intercepting ditches 7, and set up a complete surface and underground drainage system to intercept and divert surface and groundwater flowing into the fill body to maintain the stability of the slope.

[0030] 3. Excavate a foundation pit on the outside of the mountain, pour concrete enlarged foundation 2 inside, and pre-embed connecting steel bars; reserve drainage channels.

[0031] 4. Tie the column reinforcement bars, erect the formwork, and pour the concrete slab 3 as a concrete protective wall.

[0032] 5. A permeable cushion layer 5 is constructed between the mountain and the concrete slab 3, with gravel filling as the bottom layer.

[0033] 6. Apply 11 on the slope surface 1A of the mountain to ensure the stability of the slope.

[0034] 7. Lay a layer of metal mesh or impermeable geomembrane on the gravel layer.

[0035] 8. After the concrete panel reaches 90% of its design strength, pour lightweight foamed concrete, using a layered and block-by-block approach.

[0036] 9. After the high-quality foamed concrete reaches the design height, lay a layer of impermeable geomembrane to enhance crack resistance and reduce reflective cracks.

[0037] 10. Construction subgrade superstructure.

[0038] The embodiments described herein are preferred embodiments of this utility model and are not intended to limit the scope of protection of this utility model. Therefore, all equivalent changes made to the structure, shape, and principle of this utility model should be included within the scope of protection of this utility model.

Claims

1. A roadbed structure for steep slopes on highways, characterized in that: The structure includes a foundation pit excavated on the outside of the slope toe of the slope (1), a concrete enlarged foundation (2) is poured in the foundation pit, vertically extending column steel bars are tied to the pre-embedded connecting steel bars in the concrete enlarged foundation (2), the column steel bars and concrete are poured together to form a concrete slab (3), the concrete slab (3) and the slope (1) form a pouring cavity, the bottom of the pouring cavity is filled with gravel to form a permeable cushion layer (5), and lightweight foamed concrete is poured in the space of the pouring cavity on the permeable cushion layer (5) to form a filler (6); a water interception ditch (7) is excavated on the outside of the slope toe of the slope (1), the water interception ditch (7) is located on the outside of the concrete slab (3); a drainage channel (4) is reserved on the concrete slab (3), the inner end of the drainage channel (4) extends to the permeable cushion layer (5), and the right end extends downward to the outside of the concrete slab (3).

2. The highway steep slope subgrade structure as described in claim 1, characterized in that: The cross-section of the concrete enlarged foundation (2) is inverted T-shaped.

3. The highway steep slope subgrade structure according to claim 1 or 2, characterized in that: The slope (1) includes a slope surface (1A), a step surface (1B) at the top of the slope surface (1A) and a slope foot surface (1C) at the bottom of the slope surface (1A); anti-slip fixing nails (11) are driven into the slope surface (1A), with the left end of the anti-slip fixing nail (11) cast into the filling body (6) and the right end driven into the mountain body at an angle downward.

4. The highway steep slope subgrade structure according to claim 3, characterized in that: A layer of metal mesh or impermeable geomembrane is laid on the permeable cushion layer (5) to form a reinforcing layer (9).

5. The highway steep slope subgrade structure according to claim 3, characterized in that: An impermeable geomembrane is laid on top of the filler (6) to form the second reinforcing layer (10).

6. The highway steep slope subgrade structure according to claim 3, characterized in that: A glass fiber mesh is laid in the infill (6) to form a reinforcing layer three (12); along the vertical, the reinforcing layer three (12) is aligned with the stepped surface (1B) of the central slope (1).

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